In the formulation of drug compositions, it is important for the drug substance to be in a form in which it can be conveniently handled and processed. This is of importance, not only from the point of view of obtaining a commercially viable manufacturing process, but also from the point of view of subsequent manufacture of pharmaceutical formulations comprising the active compound.
Further, in the manufacture of oral drug compositions, it is important that a reliable, reproducible and constant plasma concentration profile of drug is provided following administration to a patient.
Chemical stability, solid state stability, and “shelf life” of the active ingredients are also very important factors. The drug substance, and compositions containing it, should be capable of being effectively stored over appreciable periods of time, without exhibiting a significant change in the physico-chemical characteristics of the active component, e.g. its chemical composition, density, hygroscopicity and solubility.
Amorphous materials may present problems in this regard. For example, such materials are typically more difficult to handle and to formulate, provide for unreliable solubility, and are often found to be more unstable.
Thus, in the manufacture of commercially viable and pharmaceutically acceptable drug compositions, it is important, wherever possible, to provide the drug in a substantially crystalline and stable form(s).
International patent applications WO 99/55705 and WO 99/55706 disclose a number of compounds, referred to as imidazo pyridine derivatives, which are potassium-competitive blockers of acid secretion, P-CABs, see also N. Vakil, Alimentary Pharmacology & Therapeutics, Volume 19, Issue 10, Page 1041, May 2004.